State of the art Non-linear Network Measurement Systems (NNMS) are arranged for performing measurement of the RF voltage and current waveforms at the ports of an RF and microwave device under test, under periodic Continuous Wave (CW) and modulated excitation conditions.
These measurement systems are capable of acquiring information on the non-linear RF signal behavior of a device under test compared to classical measurement techniques using well known network analyzers for analyzing the linear behavior of RF and microwave devices.
However, among others, with the growing importance of wireless communication technology, there is a need for an even more accurate characterization of the non-linear RF signal behavior of RF and microwave devices, in particular devices arranged for use with Code Division Multiple Access (CDMA) techniques.
It has been observed that state of the art NNMS are not capable of providing a complete characterization of the non-linear signal behavior of RF and microwave devices, such as amplifiers, mixers and the like under relatively large, modulated signal excitation conditions wherein DC settings of a device remain not constant, but show a dynamic behavior dependent on the modulation of the excitation signals.
One of the effects observed of this type of non-linear distortion is the broadening of the output signal spectrum relative to the input signal spectrum, which is called “spectral regrowth”.